In recent years there has been a sharply increasing awareness of possible disruptive effects on the ecology attending discharge of various pollutants into ground waters, streams, rivers, and lakes. Particularly undesirable is the large scale discharge of compounds which persist in the environment and adversely affect the qualities of our waters. As a result of government and individual concern, manufactures of detergent compositions are endeavoring to eliminate non-biodegradable synthetic organic detergent materials, e.g., branched chain alkyl benzene sulfonates, as the organic surface active agents in commercially available household laundry detergents. Similarly, at the present time they are engaged in extensive research efforts to replace polyphosphate builder constituents of such compositions so that the wash discharges from household and commercial laundries will not cause possible accumulations of phosphates in rivers and lakes.
Because of the very desirable building, sequestering and soil-suspending activities of the polyphosphates, especially the alkali metal tripolyphosphates and pyrophosphates, it has previously been difficult to eliminate them from detergent compositions without significant losses in cleaning power. Even 100% active synthetic organic detergents have not been able to produce the same cleaning effect as is obtained from combinations of such compounds and polyphosphate(s). At the present time, about the only substitute in part for the polyphosphates which appears to be able to duplicate their effects substantially is nitrilotriacetic acid or a corresponding nitrilotriacetate, which are often referred to as NTA.